Hi all,
we run a cluster of xrootd servers which provide data from multiple directories, all of which reside on *the same* filesystem. When querying the available (free, etc.) space, we get the filesystem volume *multiplied by the number of directories*.
Basically, we've got this situation:
o A single filesystem mounted at `/export/gka6201` [1].
o Inside, we have multiple sub-directories `/export/gka6201/xrootd/data-00` to `/export/gka6201/xrootd/data-15`, i.e. 16 directories.
o Xrootd server is configured to use them via `oss.space public /export/gka6201/xrootd/data*`.
o Xrootd expands this to the actual directories upon startup [2].
o When querying the space using `xrdfs spaceinfo` [3], we get 28627434496589824B - that's precisely 16 times the actual volume of 1747279937536kB.
I'm rather sure it's not an issue from serving the filesystem from multiple servers - even if just one server is active, the factor is the same.
The docs [4] mention using `oss.space` specifically for different directories on the same partition. Do I have to make additional adjustments to the configuration for such a setup? Is this potentially a bug?
Xrootd is v4.3.0, but I didn't find any such issue in the v4.4 release notes or bug tracker.
Cheers,
Max
[1]$ df -h
Filesystem 1K-blocks Used Available Use% Mounted on
...
/dev/gka6201 1747279937536 500460019712 1246819917824 29% /export/gka6201
[2]$ cat /var/log/xrootd/logs/server/xrdlog
Config effective /etc/xrootd/server/xrootd.cf oss configuration:
...
oss.space public /export/gka6201/xrootd/data-06
oss.space public /export/gka6201/xrootd/data-09
oss.space public /export/gka6201/xrootd/data-11
oss.space public /export/gka6201/xrootd/data-14
oss.space public /export/gka6201/xrootd/data-08
oss.space public /export/gka6201/xrootd/data-13
oss.space public /export/gka6201/xrootd/data-15
oss.space public /export/gka6201/xrootd/data-01
oss.space public /export/gka6201/xrootd/data-00
oss.space public /export/gka6201/xrootd/data-03
oss.space public /export/gka6201/xrootd/data-02
oss.space public /export/gka6201/xrootd/data-05
oss.space public /export/gka6201/xrootd/data-10
oss.space public /export/gka6201/xrootd/data-04
oss.space public /export/gka6201/xrootd/data-07
oss.space public /export/gka6201/xrootd/data-12
...
[3] $ xrdfs localhost:1094 spaceinfo / | grep Total
Total: 28627434496589824
...
2) File systems need not be physical partitions. When different directories on the same physical partition are specified, they are treated as different logical partitions from a space management viewpoint. This allows you to create arbitrary views of available space (e.g., by SRM static space token).